Polymers of carbon monoxide and olefins generally referred to as polyketones are well known in the art.
Within this general class of polyketone polymers, this invention is particularly concerned with the sub-class comprising linear alternating polymers of carbon monoxide and at least one ethylenically unsaturated hydrocarbon. This type of polyketone polymer is disclosed in for example, U.S. Pat. No. 4,880,865, which is herein incorporated by reference.
Phenolic resins are very well known in the art. These are thermoset resins which are used in high-temperature electrical applications such as ovens and toasters, and as engineering materials.
Blends of polyketone with other polymeric materials such as polyamide (nylon), polycarbonate, polyester, and polyacetal are known in the art. Generally, these blends are immiscible polymer mixtures, which may in certain cases exhibit utility as a result of specific property advantages. Miscible blends between polyketone and poly(vinyl phenol) are also known in the art. The present invention involves polyketones and phenolic novolacs which also comprise a fully miscible blend system.
The present invention specifically relates to the use of polyketone/novolac blends in the preparation of materials having reduced permeability to water vapor. It is known in the art that polyketones possess properties set conducive to applications in packaging for food and drink. However, some applications in this area are limited by polyketone's excessive permeability to water vapor. One approach to improve polyketone's water barrier properties while experiencing minimal sacrifice in other important properties is by strategic blending with other polymers.